SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fcfbfb42411929ded8e534138d918160b0f0e47a39975c3e0a3605ca7342f191' 
  AND token = 'DAni6tpwvfy1c2tsajNkFc/NahOwXXnahfivNOasqvE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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