SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b34ae79db91094bd4a7ac178e6db98f5f6fb92f585c05e3800535a8d45d53f1' 
  AND token = 'CXiMKlKS4Ag70w3cwGcL32RedrqXbvYySIKgiuRCJU8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}