SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ad814a673c01182f5ce211ff77c4f16052f1a453e6e833616df5b46fbbed885' 
  AND token = 'NIMUa7z3IGnZeMwWHDsQ25hznPpd5TeAl0+xuZBCSDc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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